This tests for a bug where quotes escaped by PHP when using
`preg_replace` with the `/e` modifier must be correctly unescaped
(hence the `_UnslashQuotes` function found only in PHP Markdown).
Headers below should appear exactly as they are typed (no backslash
added or removed).
Header "quoted\" again \\""
===========================
Header "quoted\" again \\""
---------------------------
### Header "quoted\" again \\"" ###
Test with tabs for `_Detab`:
Code 'block' with some "tabs" and "quotes"